Correction: Opportunities within the meat supply chain in Africa—The case of beef production in Northern Ghana

[This corrects the article DOI: 10.1371/journal.pone.0260668.].


Introduction
The developing world has been targeted by foreign direct investments for many decades. These financial inputs are usually aimed at acquiring rights to exploitable natural resources (e.g., logging, mining) or in gaining the privilege to build and operate common utilities such as roads, bridges, or sewage treatment plants. Interest in farmland and agriculture has manifested over recent years due to the explosion of the world's population and their demand for food and non-food agricultural products [1,2]. West Africa is the second most populated and rapidly urbanizing region of the continent after its Eastern segment [3]. To observe the last 30 years' periodically collected data regarding the changing size of Ghana's population, it is easy to notice that a constant increase has reached 28 million people at this time. Higher educational levels and better salaries act as breaks, correlated with a lower number of children [4]. thematic research collection and the gorgeous collaboration of German and Ghanaian researchers afforded lecturers and universities the opportunity to produce a beautiful analyzation of eating habits and provide the first prediction of weighted city-imported foodstuffs/capita/day. Sources of livestock, frozen fish, vegetables, fruits and crops are visualized in an article published in 2016 [23]. Another paper of theirs points out the role of small-town markets; this specific measurement of rural-urban connections and level of development are well described [24] (. With movement of animals, not just raw material for the meat industry is transported, but also animal diseases across countries, regions and districts. As several Ghanaian authors have published about the topic over the last several years, there are detectable and economically palpable diseases spread among animals and humans [25][26][27]. Sub-species of Escherichia coli are the major bacterial groups which need prodigious attention [28,29], but Salmonella and Staphylococcus sp. are also occurring as emergent, harmful, microbe groups in the meat supply chain of the Tamale Metropolis [30][31][32]). Our research aims to investigate how these agricultural value chains are working in Northern Ghana and how to develop them. In the first part of the paper, we provide an overview of the conditions for agricultural production in Northern Ghana, to help the better understanding of the difficulties of the sector we investigated. Within this context, we had the goals to draw the attention to the agricultural potential of the Savannah belt, in particular the meat sector and related educational activities and to collect a useful dataset, what could serve as fertile soil and starting point of further studies.
After introducing the methodology toolset we used, the results of the research are highlighted, followed by the conclusions, including the implications of the research results as well.

Conditions of Tamale, Northern Ghana
Ghana can be divided into two very different areas: Southern Ghana and Northern Ghana. Their differences lie not only in the periodically changing weather (in the south, there are two rainy and two dry seasons while in the north, there is a short rainy and a longer dry season), but also in their tribal-, religious diversity, and related traditions. As we are move away from the Golden Coast of the Gulf of Guinea and heading towards the North, conditions require a resilient person. Low humidity and unbearable heat are the results of infrequent rains. A wellknown publication-"Traditional recipes from the Northern Region of Ghana" [33]-includes almost all the cultivated crops, vegetables, fruits, spices and domesticated animals that people traditionally prepare to eat and drink throughout their entire lives.
As we have mentioned, the fast-growing urban population is becoming less and less committed to any form of food production activity [4], but 45% of Ghana's rural population is still engaged in agriculture [34] (. In the Economic Capital of Dagbon Kingdom, Tamale, only 20% of the population undertake any kind of agriculture-related work. Despite the fact that our city of study is surrounded by hundreds of communities, Tamale still maintains importance in transportation, trade, logistics and industry [35] Interesting fact, that since independence in March 1957, the traditional kingdom of Tamale (as much as all other such formations of Ghana) assumed customary role.
Tamale had been selected because of its

Research methodology
From April 2019 -December 2019, primary data collections were carried out mainly within the Tamale Metropolis and Nyankpala community. Due to the high Muslim population percentage, we had to avoid any food-related data collection in May and June because of Ramadan; denoting that Muslims are accordingly reducing their diet to include only tea and bread and consumption of any other food products (such as meat) diminish.
During the overall collection of data, we focused on the meat supply and value chain of the Tamale Metropolis.
To understand the basics of animal production and live animal flows, especially importation procedures and primary trading methods of livestock, we visited four governmental institutes to conduct casual interviews. Those institutes were: Observing the cattle transportation process, livestock was either transported one by one in small vehicles or in crowded trucks at speed throughout the country with fast delivery to slaughterhouses and meat manufacturers ensuing. Within the Tamale Metropolis and Nyankpala, the four main processing factories were: 1. Tamale Main Abattoir; 2. Gee's Fresh Point; 3. Farm Gate; 4. Meat Unit, UDS.
Eleven cold stores in the Tamale Metropolis were also visited and employees interviewed by us.
To estimate meat demand in the Tamale Metropolis, we carried out a large-scale survey within the population. Demand of particular meat products was estimated (consumer side). Furthermore, we also measured the awareness of processed meat products.
In total, within one week (between the 30th of September and the 5 th of November), we interviewed 334 people in the centre of Tamale, around and inside the Main Market.

Data collection
2.1.1. Primary data. We had the opportunity to join the UDS Meat Unit team for 7 months long. Here, we could see the basics of meat production technologies and trade. They brought me to Savelugu to buy animals and explain the complete methods of livestock trading, transportation and market periodicity. The level of meat production technologies, capacity of facilities, and basic data about production yields were measured and collected. We discussed technological utilization and use of local materials like spices, fats and oils. As far as our situation allowed it, we tried to assess the limitations of production facilities, utility gaps, and locational advantages and disadvantages. First, we designed a quantitative, semi-structured, questionnaire and successfully interviewed the 4 biggest slaughterhouses/manufacturers (Tamale Abattoir; UDS Meat Unit; Gee's Fresh Point; FarmGate) to map out local industrial scale. First of all, we asked them to answer 9 questions about daily operations, type of activities (slaughterhouse/boning plant/further processing facility), production quantities, animal supply and origin. The number of employees and their levels of education were also recorded. Every time we visited a firm, the focus was set on specific topics and strictly noted the answers. These topics were: 1. Origin of animals 2. Processing technologies, processing level of products, storage methods 3. Distribution and main markets 4. Employees, education level

Advantages and disadvantages of Tamale as an industrial centre
Secondly, one semi-structured, qualitative questionnaire for 11 randomly selected cold stores (including 15 questions) was designed to measure the origin of products, the quality and reliability of local manufacturers, biggest consumers and the distribution system. During our dialogues, it was possible to shine a light on some specific trade habits, consumer preferences and stores/refrigerator capacities. To complete our insight into the last part of the supply chain, we reached out to 334 randomly selected inhabitants around Tamale Main Market with a finely structured questionnaire (including 21 questions) to measure special weekly meat consumption and knowledge about origin and preference of meat products. First of all, we asked them to indicate their weekly number of breakfasts, lunch, supper and snack intakes. They had to indicate whether beef, chicken, fish, and pork. Secondly, we were interested in their knowledge about the origin of meat products (domestic or imported), and their shopping habits within the city. The final few questions were designed to garner an idea about the storage of purchased meat. All questions were meat related.

Sources of secondary data.
Portions of secondary data were collected from a Tamale-based association named 'Ghana Developing Communities Association' to indicate the scale and role of animal markets and, furthermore, the 'South orientated' live animal trade. Meat Unit, the meat manufacturer of the University for Development Studies in Nyankpala, provided data on cattle carcasses and offal weights. Estimation of population and other sociorelated data was provided by the United Nation Data Base and FAOStat.

Results
To prove the credibility of this publication, we compared data published in Population and Housing Census 2010 by the Ghanaian Government to the descriptive consumer information collected by us ( Table 1).
The only conspicuous difference appearing is with school attainments. It seems that educational levels have been growing. This may be resultant of the implementation of a free high school system by the government in 2017.

Role of animal markets
Small town markets are the first window of opportunity where farmers introduce their food products to wholesale or retail businesses. Big ruminants like cattle are usually trekking the whole year around West Africa (Niger, Mali, Burkina Faso) and twice a year reach North Ghana in what seems as a highly appreciated market because of its constantly solvent demand and relatively well-operated meat industry.
3.1.1. Spatial location, monthly livestock flow and time series analyzation of pointed animal markets. Four primer wholesale northern animal markets were mapped out to indicate southern-orientated live animal transport. The importation of livestock is usually originating from Burkina Faso and Togo. The green area indicates major domestic production of ruminants (North Ghana), while the grey area shows usual destinations and solvent demand (south Ghana). The N10 main road deserves special attention in terms of food transportation (Fig 1).

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Opportunities within the meat supply chain in Africa-The case of beef production in Northern Ghana Consequently, the reasons why we did not want to attach the markets together and present it as one whole dataset: 1) There are huge differences between markets in the number of presented cattle. It is worth seeing the gaps between them; 2) Periodical shifts between markets are noticeable in Figs 2 and 3) Before we will have enough data (at least 30 months/market), it is not acceptable to run them through any statistical analyzation. Only the datasets from Tamale and Bawku hit the bar with its 36 impulses.; 4) Four animal markets do not cover the entire north Ghanaian cattle trade existence.
Huge differences between size of markets can be determined around Tamale. As the main northern city with a market operating every day, gives rise to a relatively high turnover of cattle during the whole year. Pusiga as the first trade point in the north-western tip of Ghana, also varies from 1,000 up to 6,500 heads of cattle.
Every Twelfth month peak, in December, represents Christmas. Bawku shows the most outstanding values currently, although Christianity is not completely obvious there. A correlogram for Bawku's dataset shows a significant (p<0,01) autocorrelation within every twelve

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Opportunities within the meat supply chain in Africa-The case of beef production in Northern Ghana months. A partial autocorrelation outlines almost the same values, so we can declare that both datasets about Bawku's cattle market (presented and sold) are recurring (Fig 3).
The Tamale cattle market correlogram denotes that every 6th and every 12th previous data correlate with each other. Both autocorrelation and partial autocorrelation in slip level 6 show a negative autocorrelation. That means, data with 6 months' difference between them are inversely proportional to each other. It could refer to the changing of seasons and also religious holidays. Yearly periodicity of the market would also mean a predictable variance, but partial autocorrelation does not verify it (Fig 4) Average difference between the means is 116 kg. This equals the summary weight of head, legs and internal organs. Both datasets are distorted. Skewness and kurtosis show abnormal distribution as per the Shapiro-Wilk-test with p-value lower than 0,01. In the case of random choice, positive skewness means that our chance is higher in finding a carcass below the mean weight (representing 120 kg and 236 kg). Median is the 'middle' value in the list of carcass weights which shows us where the middle value is in the wide range of data. If it occurs below the mean, it means that carcasses are usually lighter rather than heavy weighted (medians are 108 kg and 215 kg). Kurtosis measures the tail heaviness of the distribution, which shows negativity in both cases (-0,538 and -0,927), what means the distribution curve is wide and heavyset. Cattle carcasses and live weights vary in wide range due to different levels of their maturity and types of breeds such as Zebu, West African Short Horn and Sanga (Teye GA and WK Sunkwa, 2010). (Fig 5) Our main goal was to give a description, the relationship between 'live weight' and 'technologically useful weight'. Hide blood content and weight had been also added to 'edible weight' under the term 'live weight'. According to the Ministry of Agriculture and Rural Development, South Africa, hide weight in terms of cattle in percentages of live weight is about 7% (Ministry of Agriculture and Rural Development, Province Kwazulu-Natal, South Africa). Blood content of matured cattle in percentages of live weight varies. An article also from South Africa (Agbeniga and Webb, 2012) indicates average blood loss to be 2.4% of the live weight, while another from Turkey shows 3.1% in the case of conventional stunning and eviscerating (MH Anil et al. 2006). We have taken the average of the two and calculated with 2.75% blood content. Equalization between warm quarters weight and live weight is as follows:

Estimated consumption quantities /personal survey/.
To extract a weekly portion of consumed meat by type, we have summarized the answers provided by every single consumer. Main meat types of our interest were beef, chicken, fish and pork. Calculation of exact portion from the given intervals ( Table 2): The fact that 334 persons had filled out the survey, enabled us to divide the cumulative numbers to see the average portion of consumed meat by type and meal. Snacks do not play a major role in the diet of Tamale men; frequencies of answers were too low to calculate with. (Fig 6) Consumed portions of different meat types were also calculated (Table 3). Now, we should figure out the average grams of portions. we took three pieces of cooked/fried meat from every type and weighed them. One piece of meat is shown as being among the following average weights: beef-25g; chicken-50g; fish-25g; pork-50g. During our time in Ghana, every time we ate in Ghanaian society, we consistently counted the pieces of meat on the plate. Beef is shown as 2 pieces, chicken shown as 1, fish shown as 2 and pork shown as 1. Multiplying the portions with the pieces, we came to an averagely-consumed number of cooked grams of meat per capita. To be able to calculate the raw meat demand per person, we had to figure out the percentage of cooking loss. We were also involved in some kitchen work, and cooking losses showed  variation between them. Chicken and fish have lost averagely 15% of their raw weight during deep frying. Pieces of beef and pork were tougher, and losses were no more than 5%. With this calculation method, raw meat demand seems like an available data for further studies. Raw fish demand reaches the highest level among the four meat types we have measured. It shows 61 grams per capita per day. Beef-and chicken-meat share second place-closely equal at 45 and 48 grams. Low-level pork consumption (11 grams/capita/day) indicates that Tamale is mainly populated by Muslims (Fig 7).
To extrapolate these differentiated portions' quantities for the whole population of Tamale (523.568), we need to multiply portion's weights with the size of population. Because we are assuming that consumer habits did not change between the survey time (2019) and nowadays (2020), daily quantities of raw meat demand are estimated as indicated on Table 4:

Estimated production quantities /factory visit/.
In this section, we are going to represent production quantities, focusing on beef production. Beef is our main interest due to • it's acceptation by every religious group • forms of a relatively large size which could serve as material for further processing • cattle are adapted to the savannah climate

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Opportunities within the meat supply chain in Africa-The case of beef production in Northern Ghana Production quantities are varying between manufacturers. For example, Tamale Main Abattoir deals only with cattle and small ruminant slaughtering, while Farm Gate and UDS Meat Unit provide a wide range of processed meat products. Table 5 shows the weekly number of slaughtered animals by type per firm.
As a case study from Kenya published in 1991 by the Food and Agricultural Organization (Kassam et al., 1991) shows, domesticated tropical animals can be determined using the Tropical Livestock Unit. Herd structures have been defined in terms of number of heads of animals as well as in terms of referencing what Tropical Livestock Unit (TLU) defined as a mature animal weighing 250 kg. Surprisingly, our own calculated dataset, collected from the University for Development Studies, shows a slightly higher live weight of cattle (Fig 8).
The aggregated beef (edible weight) production quantity of Tamale is estimated to be 89 tons/week (Table 6). Numbers depend on the 4 main slaughterhouses' declarations.

Deficit of production.
Comparison of our processed quantitative data between beef production and consumption outlines a relatively high production deficit. The following tables (Tables 7 and 8) show the daily deficit of beef in tons and lacking number of cattle.

Conclusions and limitations
In today's sense, when local events become global within a second, the construction of a secure and robust social system cannot ignore public service. Not just bad recipes or harmful religious  and political ideologies are sweeping through the world, showing extremities in the light of goodness, but both conventionally and revolutionary solutions for local problems are popping up. What could we share with the world if we have nothing to show? Development of public services offers the opportunity to (1) gaining market power for ourselves while losing market power for others, (2) indirect takeover of control on political and civil societies while losing control for others, (3) to win allies and friends on one hand, potentially losing allies and friends on the other. The innumerable frontlines illustrate a labyrinth that could lead us to create and follow a bad strategy with ease, where dead ends appear in the forms of commodity duties, embargos, increased military presence, bioterrorism or even disrupted food security. With well-designed and structured decision making, we could have something to offer. First, we would like to turn the focus on the credibility of this paper. Descriptive statistics of the accomplished consumer analysis allow us to see the 2019 surveyed population shows a similarity to the published data by Ghana's Government in the 2010 Housing Census. Not just the estimation of current consumer eating habits and basic preferences, but later research and development strategies could be planted into this ground bedded by us.
Secondly, we need to add supplements to the sections which deal with the quantitative dataset of consumption. Unfortunately, chevon and mutton, as major sources of animal-based protein, were not measured in the consumer survey. It is a problem because people in Northern Ghana, especially Muslims, highly appreciate these types of meats. Addition of these data would result in a more accurate estimation of consumption. The currently measured 60.2 kg annual meat intake per person seems like an over-calculated estimation compared to the 9.32 kg published by FAO in 2017. Knowing Ghanaian food recipes which do often contain more than one type of meat (almost all stew types include smoked or dried fish e.g. fish bra leaves soup) should remind us to gently handle consumption data although we can declare that an effective traceability system does not exist in Ghana. For this reason, macroeconomic essays are not able to provide as accurate measurements as microeconomic research can do. Referring to Karg (2016) and Akoto-Danso (2019), the daily incoming quantity of livestock to Tamale in live weight per person is about 100 grams. That means, annually, 33.26 kg of edible weight. In addition, the production output of urban and peri-urban animal husbandry of Tamale and the trade quantity of frozen meat products by cold stores would result in the total meat supply of Tamale. In this way of thinking, annual meat consumption within the Tamale Metropolis per person is estimated to hold a value between 33.3 kg and 60.2 kg. As Tamale is showing this high-volume consumption on its own, a large part of the supply arrives not just from outside of the city, but outside of the country; the time has come to start thinking about long-term collaborations between local and foreign knowledge.
In the case of red meat production, the location of Tamale compared to other major southern cities (e.g. Accra, Kumasi, Sekondi-Takoradi, Sunyani, Techiman etc.) seems definitely more advantageous. As we are farther and farther from the south, we are also getting closer and closer to northern pastoral and grazing areas of cattle and small ruminants. After spatial analyses of grazing areas, animal markets, trading routes and witnessing the descriptions of basic macroeconomic differences within Ghana; we must conclude that live animal trade is south-orientated, where traders are able to bargain higher prices. Due to northern locational advantages, the price of animals could be reduced. The presumably cheaper workforce and dozens of unemployed young males could also alleviate the financial burdens. Cattle have received a deeper overview because of their large meat mass and proven meat production technologies that could be implemented within local conditions. All other calculated models between cattle' live weight and technologically-useful or 'edible weight is aimed to help further planning. With the published models, we can estimate the needed number of cattle for sufficient production.
Actually, neither agricultural-nor food-production can stand on one leg. A knowledgeequipped and practiced, skilled, workforce, technological and infrastructural development, make up large parts of a successfully-operating firm.
First, technological development should be aimed at avoiding diseases and contaminations spread through blood, faeces, and other internal fluids. The technological transformation of the floor (e.g., metal lattice instead of adjacent tiles) needs to be implemented to secure a long shelf life of products. Under other infrastructural and technological development, we mean construction of high-capacity cold stores because the thirty years old method of producing corned-canned beef by Zuarungu Meat Factory in nearby Bolgatanga-a product that does not need cooling-cannot compete with contemporary popular sausage products which do need a cool environment.
Establishment of an Agricultural Vocational School, where-among various professionsbutchering should be highlighted. In Dagomba culture, butchers (Nakohama) form a highly Scholarship programs offered by the European Union (EU) have to be reformed into traineeships. Dual tertiary education means students are engaged 50-50% by an educational institute and a company. Students should receive a monthly scholarship by the EU (any public institution), but the whole wage of the traineeship should be transferred in one instance at the end of the program (by the company). The student (after returning to Ghana) has to invest this amount of money into one of those agricultural practices that he/she has learned in the EU. The process need to be controlled by supervisors.
Collection of different data about animal markets and stock flows, meat-manufacturers, cold stores, dressing percentages, structure of education are all lined up in the queue of Tamale's advantages. Upcoming development strategies have to include plans like: